Yang, B. et al. Cell 158, 945–958 (2014).

Organs such as the brain, kidney or lungs depend on a complex three-dimensional organization for their function. Yang et al. now describe an improved tissue 'clearing' protocol that preserves structural integrity even at the cellular level while enabling the imaging of structures deep inside the tissue. The approach combines an optimized set of clearing reagents, including acrylamide and a strong detergent, with a suitable embedding medium. The tissue clearing process can be sped up by perfusing the clearing agents into organs or even whole animals. The procedure is compatible with histological techniques, immunohistochemistry and fluorescence in situ hybridization and can be applied to a variety of organs. The approach allows tissues and organs to be studied in their intact structural context.